Schedule II - Valuation and Qualifying Accounts (Detail) - Allowance for expected credit losses [Member] - USD ($)	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 2,823,000	$ 2,562,000	$ 3,274,000
Additions Charged to Cost and Expenses	1,828,000	1,216,000	158,000
Deductions	(406,000)	(955,000)	(870,000)
Balance at End of Year	$ 4,245,000	$ 2,823,000	$ 2,562,000